Disposable products have revolutionized modern lifestyle and are of great convenience to society. Such products generally are relatively inexpensive, sanitary and quick and easy to use. Disposal of such products, however, is a concern as landfills close and incineration contributes to urban smog and pollution. Consequently, there is an urgent need for disposable products that can be disposed of without dumping or incineration. An ideal disposal alternative would be the use of municipal sewage treatment plants and private residential septic systems. Products suited for disposal in sewage systems that can be flushed down a conventional toilet are termed "flushable." An essential feature of flushable products is that they must have sufficient strength for their intended use, yet lose structural integrity upon contact with water.
Numerous consumer products, which were formerly unable to be disposed of in a conventional toilet, are made flushable today. Such products include water-soluble films, wipes, tampon applicators, etc. However, many consumer products have remained unflushable.
One such product that has remained unflushable to date is release liners. Release liners are used to temporarily cover an adhesive layer before use in many personal care products. The release liner provides protection for the adhesive layer against exposure to materials, which might negatively affect the ability of the adhesive strip to adhere to a desired substrate, and provides protection against undesired, premature adhesion to a substrate. Conventional release liners comprise a paper substrate coated with a release coating. The release coating is formulated to provide very little adhesion of the coated paper to any other substrate, particularly pressure-sensitive, hot-melt adhesives, so the release liner may be easily removed from the adhesive strip without disturbing the adhesive strip. Typically, release coatings comprise a silicone-containing polymeric material.
Release liners are used in many personal care products. For example, many sanitary napkins have an adhesive strip on the backside of the napkin (the napkin surface opposite to the body-contacting surface) to fix the napkin to an undergarment and hold the napkin in place against the body. Before use, the adhesive strip is protected with a peelable release liner. Once removed, the peelable release liner must be discarded. Since peelable release liners are typically silicone-coated paper, the release liners do not disperse in water; consequently, disposal options are limited to depositing the release liner in a trash receptacle. Although disposing of conventional release liners in a toilet would be convenient to the consumer, such disposal potentially creates blockages in the toilet or household sewer line.
What is needed in the art is a flushable release sheet, which can be discarded and then flushed in a conventional toilet. Such a flushable release liner would offer convenience to the consumer, and not cause problems such as blockages in the sewage transport process.